When petroleum or petroleum products (sometimes generically referred to as “oil”) spills in a body of water, the oil will generally collect on the surface of the water due to its buoyancy and immiscibility with water. Floating oil poses numerous environmental hazards. Watercraft cannot traverse the slick unless specifically equipped to do so; otherwise they risk damage to the craft, ignition of the slick, or spreading the slick. Consequently, oil spills can restrict or eliminate recreational and commercial boating and shipping. In extreme cases, an oil spill can close an entire port. Oil is toxic to most marine life, including fish, mammals, turtles, and sea birds. These creatures are often either commercially valuable, at risk of extinction, or both. Oil is also toxic and carcinogenic to humans. An oil slick can make water inhospitable to swimmers, render seafood inedible, and can render beaches unpleasant or dangerous to recreational and commercial use. Oil is also toxic to terrestrial plants and animals which can be exposed at the shoreline. Marshes and swamps can be particularly impacted by oil spills. Because such wetlands serve to reduce flooding and serve as hatcheries for valuable aquatic and marine species, their destruction by oil spills is of specific concern. An oil spill can therefore cause entire communities and industries to suffer economic disruption.
Once the oil has formed a slick on the surface, it will move in response to tide, current or winds. Floating oil slowly absorbs water and debris, which increases the oil's bulk density. The lighter components of the oil evaporate (creating noxious fumes), while the heavier components remain. These processes cause the oil to lose is buoyancy, and sink. Once the oil sinks, it still retains its toxic properties. However, oil is very difficult to collect or degrade once it is no longer on the surface of the water. As a result, efforts to remediate oil spills focus on containing and treating the spill while it is still on the surface. This is usually done by removing the oil with hoses and skimmers. Oil will also naturally degrade due to the metabolism of bacteria, but this occurs much more slowly if the oil sinks, due to lower concentrations of oxygen at greater depths.
Traditionally oil is contained, or its movement slowed, by the placement of floating booms. The boom forms a barrier on the surface of the water to a certain depth. The slick can thus be prevented from spreading to the opposite side of the boom. Containment of the oil in this manner facilitates clean-up of the contaminated water and aquatic environment in general. Oil booms also are used to stop patches of oil from impacting coastal areas, or migrating into areas in which strong currents could further transport the slick.
The crude oil that oil booms are used to contain is often a heavy, sticky material. When oil weathers on the surface of water, it can form emulsions with foamy or gelatinous texture (when water is suspended in oil, this is known as “mousse”). As a result, oil booms that have been deployed become contaminated with oil and debris. Oil booms also may become fouled with barnacles, algae, or other organisms. Consequently, an oil boom may need to be cleaned or decontaminated before being stored or redeployed.
Currently there is no effective way to decontaminate oil booms. Typically, workers manually scrape and scrub the boom. This process is manually intensive, slow, and expensive. It has the potential to expose workers to toxic and carcinogenic oil components, and can yield inconsistent results.
Thus, there exists a need for a way to effectively, quickly, safely, and cost effectively decontaminate oil booms.